Mobile load handling or lifting machines

ABSTRACT

A mobile machine for load handling or lifting purposes is disclosed in which an attachment head, for receiving load handling means attached to it, is carried for raising and lowering movement by forwardly extending parallel motion linkage pivotally connected to a forwardly extendible and rearwardly retractable member of a telescopic boom longitudinally carried by an extendible wheeled chassis of the machine, the boom being also arranged to be bodily advanced or retracted relative to the chassis by support linkage which is linked to the chassis for fore and aft extension of the latter to counteract the machine against forward tipping movement on such bodily advance of the telescopic boom.

[451 June 20, 1972 [54] MOBILE LOAD HANDLING OR LIFTING MACHINES [72]Inventor: Donald George Shaw, Albrighton, England [73] Assignee: Shaw,Trew & Smlth Limited, Shifnal,

Shropshire, England; a part interest [22] Filed: July 23, 1970 [21]Appl.No.: 57,536

2,989,202 6/1961 Canniere et al ..214/730 X 3,305,116 2/1967 McKee2,990,072 6/ 1961 Mindrum .214! l 41 X Primary Examiner-Gerald M.Forlenza Assistant Examiner-Jerold M. Forsberg Attomey-Watson, Cole,Grindle & Watson [57] ABSTRACT A mobile machine for load handling orlifting purposes is disclosed in which an attachment head, for receivingload handling means attached to it, is carried for raising and loweringmovement by forwardly extending parallel motion linkage pivotallyconnected to a forwardly extendible and rearwardly retractable member ofa telescopic boom longitudinally carried by an extendible wheeledchassis of the machine, the boom being also arranged to be bodilyadvanced or retracted relative to the chassis by'support linkage whichis linked to the chassis for fore and aft extension of the latter tocounteract the machine against forward tipping movement on such bodilyadvance of the telescopic boom.

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BY ATTORNEY PATENTEDJUH 20 I972 SHEET 2 BF 2 FIG.2.

INVENTOR DQNALD 65024-2 S BYfihwa ATTORNEY MOBILE LOAD HANDLING OF.LIFTING MACHINES This invention relates to load handling or liftingmachines such as cranes, fork lift trucks, excavators (e.g. trenchdiggers) or bucket or scoop loaders or similar machines and has for itsobject to provide a mobile machine capable of readily meeting widelyvaried operating requirements. Practical advantages in this and otherrespects will be apparent from the following disclosure.

In a practical embodiment of the invention, the construction andarrangement of the machine is as follows reference being had to theaccompanying drawings in which:

FIG. 1 is a side elevation of the machine, and

FIG. 2 is a rear view.

The machine is supported on front and rear pairs of ground wheels 3,4 ofwhich the front wheels 3 are arranged to be intumed (see FIG. 2) forslewing purposes and are also forwardly extendible relative to the rearwheels 4 in a manner to be hereinafter described. For this purpose arear axle beam 8 carrying the rear wheels 4 is mounted from a rearstructure 7 of the chassis 6,7 of the machine while a front beam 2carrying the front wheels 3 is mounted from a forward chassis structure6 which is slidable in a fore and aft direction relative to the rearchassis structure 7.

All four wheels 3,4 are preferably independently driven by hydraulicmotors operatively connected thereto (not shown) while intuming of thefront wheels 3 can be effected by hydraulic rams. When the front wheels3 are intumed slewing movement may be effected about the mid pointbetween the centers of the rear wheels 4 and/or about the center of aretractable turntable which is lowered into contact with the ground forthe purpose while the rear wheels 4 are steerable such as by hydraulicram operation for travelling movement of the machine i.e. with the frontwheels 3 in the straight ahead position.

The front of the machine is provided with an attachment head 9 forreceiving attached thereto any one of a variety of load handling orlifting devices such as a bucket or scoop loader as at 99, fork lift,crane jib, hydraulic grab, or hydraulic rotating head or a bulldozerblade. The attachment head 9 is arranged to be raised and lowered by apair of arms 12 pivotally one at each side at 18 from longitudinalsupport means consisting of a horizontal telescopic jib or boom assembly1, the arms 12 being operated for such movement by hydraulic rams 13,acting between the arms 12 and brackets 14 depending from an innermember of the telescopic boom 1, which latter is shown consisting ofinner and outer tubular members 10,11 of rectangular cross section. Forthis purpose the arms 12 are pivotally mounted at 18 from the innermember 10.

In order to maintain the attachment head 9 in substantially the sameattitude as it is raised and lowered and by means of a further arm 15 inconjunction with each lifting arm 12, a parallel link motion is effectedby means of links 16 pivotally connected between the forward ends of thearms 12 and 15, each further or upper arm 15 being pivoted at itsrearward end to an upright 17 extending from the inner member 10 of thetelescopic boom 1 through a corresponding longitudinal slot 110 in theouter member 11, which slots lla also permit the connection of the arms12 and the rear brackets 14, to the inner member 10 and their movementrelative to the outer member 11 in a manner to be hereinafter described.As the arms 12 are raised and lowered, the forward links 16 remainsubstantially vertical and parallel to the rear uprights 17 while theforward links 16 carry a hydraulic ram 19 for effecting forward andrearward tilting of the attachment head 9.

In FIG. 1 the machine is shown in a retracted condition with theattachment head 9 lowered and capable of being raised through an arcindicated by the arrow R. However, for advancing the attachment head 9to a forward operating position together with forward extension of thefront wheels 3 in order to counteract forward tipping movement of themachine when operated under load in this way, the operation is asfollows:

The outer member 11 of the telescopic boom 1 is pivotally supported at23 by pairs of parallel links 20,21 (shown rearwardly inclined inFIG. 1) from the rear chassis structure 7 and of which the forward links20 are arranged for hydraulic ram operation at 22 from the rear chassisstructure 7.

0n the ram 22 being forwardly extended the links 20,21 are angularlymoved about their pivotal mountings 24 on the rear chassis structure 7with an over-center action so as to assume a similar forwardly inclinedposition. By such movement the links 20,21 forwardly advance bodily thecomplete telescopic boom 1 together with everything carried by thelatter, viz the attachment head lifting arm assembly 12,15,16 andhydraulic rams 13 operating the latter together with the supportbrackets 14. Thus the attachment head 9 may be operated from theadvanced boom 1 in the same manner with pivotal movement of the arms 12at 18 taking place at or about the point indicated at A. At the sametime further links 25 pivotally connected from the rear links 21 at 26to the front axle beam 2 at 27 cause the latter to be advanced as theparal lel links 20,21 perform their angular over-center movement, theforwardly advanced position of the front wheels being indicated at 3a.

Although the pivotal connection 27 of the links 25 to the forwardchassis structure 6 is shown coincident with the pivotal connection 24of the forward links 20 to the rear chassis structure 7 in FIG. 1, it isto be understood that such connections 24,27 are separate from oneanother and that only the connection 27 is able to move forwardly andrearwardly with the forward chassis structure 6.

In an alternative or additional mode of advancing the attachment head 9for light load handling either with the boom 1 retracted or advanced(i.e. with or without forward extension of the front wheels 3) the innermember 10 of the boom 1 is advanced forwardly in a telescopic mannerrelative to the outer member 11 by a hydraulic ram 29 within the innermember 10 and acting between the latter and bracket support 30 withinthe rear end of the outer member 11.

By such operation of the inner member 10 the pivotal mounting 18 of thearm assembly 12,15,16 thereon carrying the attachment head 9 togetherwith the bracket support 14 of the operating rams 13 to the latter areadvanced forwardly as required, the furtherrnost position of the armpivotal mounting 18 being at the forward end of the slots 11a i.e. atthe position A when the boom 1 is in the retracted position shown.However when the boom 1 is advanced by over-center angular movement ofthe parallel links 20,21 together with forward extension of the frontwheels 3 as already described, advance of the inner member 10 relativeto the outer member 1 l as just described enables the pivotal mounting18 of the arms 12 to assume a position indicated at B for long reachoperation of the attachment head 9 relative to the machine. Thus theextent to which the attachment head 9 can be advanced can beconsiderably varied according to operating requirements together withforward extension of the front wheels 3 as necessary to counteractforward tipping of the machine.

An internal combustion engine 31 is shown carried as a counterweight atthe rear of the rear chassis structure 7 and drives hydraulic pumps tothe various hydraulic rams and motors of the machine, the hydraulicsystem being controlled from a control position or cab indicated at 32and carried by the rear chassis structure 7. Although the arrangementdescribed and shown is preferred, if desired the front wheels 3 may besteerable for travelling purposes with the rear wheels 4 arranged forintuming movement when slewing is required. For this latter purpose aretractable turntable 5 may be mounted from the forward chassisstructure 6 between the front wheels 3.

What I claim is:

l. A mobile machine for load handling purposes comprising a wheeledchassis consisting of a forward wheeled chassis structure slidablyengaging a rear wheeled chassis structure for fore and aft chassisextension and retraction of the machine; a telescopic boomlongitudinally carried by said rear chassis structure and comprising twomembers of which one of said members is forwardly extendible andrearwardly retractable relative to the other of said members in atelescopic manner; ram means acting between said members of saidtelescopic boom for effecting forward extension and rearward retractionof the said one member relative to said other member; forwardlyextending parallel motion lifting and lowering linkage pivotallyconnected to the said one member of said telescopic boom; an attachmenthead for receiving load handling means carried by the forward end ofsaid parallel motion linkage; ram means acting between said one memberof said telescopic boom and said parallel motion linkage for angularlyraising and lowering said linkage and said attachment head about saidpivotal connection of said linkage to said one member; angularly movablesupport linkage carrying said telescopic boom from said rear wheeledchassis structure; ram means acting between said rear wheeled chassisstructure and said angularly movable support linkage in order to bodilyadvance and retract said telescopic boom and said parallel motionlinkage and said attachment head carried thereby relative to saidwheeled chassis; and connecting linkage pivotally connected between saidangularly movable support linkage and said forward wheeled chassisstructure whereby, on ram operation of said support linkage to bodilyadvance said telescopic boom, fore and aft extension of said wheeledchassis is effected to counteract any forward tipping of the machine.

2. The mobile machine for load handling purposes, according to claim 1,wherein said telescopic boom comprises an outer tubular member and aninner member slidable for relative forward extension and rearwardretraction within said outer tubular member, said parallel motionlifting and lowering linkage being pivotally connected to said innermember through longitudinal slots in said outer member which slots alsopermit forward and rearward movement of said parallel motion linkagerelative to said outer member.

1. A mobile machine for load handling purposes comprising a wheeledchassis consisting of a forward wheeled chassis structure slidablyengaging a rear wheeled chassis structure for fore and aft chassisextension and retraction of the machine; a telescopic boomlongitudinally carried by said rear chassis structure and comprising twomembers of which one of said members is forwardly extendible andrearwardly retractable relative to the other of said members in atelescopic manner; ram means acting between said members of saidtelescopic boom for effecting forward extension and rearward retractionof the said one member relative to said other member; forwardlyextending parallel motion lifting and lowering linkage pivotallyconnected to the said one member of said telescopic boom; an attachmenthead for receiving load handling means carried by the forward end ofsaid parallel motion linkage; ram means acting between said one memberof said telescopic boom and said parallel motion linkage for angularlyraising and lowering said linkage and said attachment head about saidpivotal connection of said linkage to said one member; angularly movablesupport linkage carrying said telescopic boom from said rear wheeledchassis structure; ram means acting between said rear wheeled chassisstructure and said angularly movable support linkage in order to bodilyadvance and retract said telescopic boom and said parallel motionlinkage and said attachment head carried thereby relative to saidwheeled chassis; and connecting linkage pivotally connected between saidangularly movable support linkage and said forward wheeled chassisstructure whereby, on ram operation of said support linkage to bodilyadvance said telescopic boom, fore and aft extension of said wheeledchassis is effected to counteract any forward tipping of the machine. 2.The mobile machine for load handling purposes, according to claim 1,wherein said telescopic boom comprises an outer tubular member and aninner member slidable for relative forward extension and rearwardretraction within said outer tubular member, said parallel motionlifting and lowering linkage being pivotally connected to said innermember through longitudinal slots in said outer member which slots alsopermit forward and rearward movement of said parallel motion linkagerelative to said outer member.